I think just the fact the images wouldn't be the same size would keep you from getting accurate results from any action.You might be able to transform the edges using a percentage value, but again there would be way too many varialbes.

If you want to give it a try, paste the previously posted text into a new file in ExtendScript Toolkit (part of Photoshop’s installation, Applications/Utilities/Adobe Utilities/ExtendScript Toolkit CS4 or /Applications/Utilities/Adobe Utilities-CS5/ExtendScript Toolkit CS5) and save it as a jsx-file into Photoshop’s Presets/Scripts-folder.

After restarting Photoshop the Script should be available under File > Scripts and can be assigned a Keyboard Shortcut directly, recorded into an Action, (in CS4 and CS5) be used in a Configurator-Panel or started from ExtendScript Toolkit directly.

That's an interesting action, but I thought the expected output was different than what this action produces. First, I didn't think image cropping would have been ok (maybe the OP expects this or is ok with cropping). Secondly, I kept getting caught up in how the right edge was going to actually be skewed (as decreasing in size perspectively off into the distance). This action appears to just visually trick the eye (again which may be what the OP wanted or is ok with). Like I said, just that aspect alone is where I kept getting stuck in how this would be possible without some manual manipulation.